- Video report by ITV News correspondent Liz Summers
Old round pound coins will cease to be legal tender after the weekend - but some shops will still be accepting them after the deadline.
Businesses can refuse to take the old pound coins from midnight on Sunday 15 October and will not be allowed to give the old coins as change.
Over the past six months, over 1.2 billion round pound coins have been returned but around 500 million old coins are still in circulation.
They were replaced by the new 12-sided pound coin in March. It resembles the old threepenny bit and boasts new high-tech security features to thwart counterfeiters.
The round pound coin was first produced by the Royal Mint in April 1983 to replace £1 notes.
Discount retailer Poundland has said it will "ignore" the Royal Mint's deadline and continue to accept old £1 coins in more than 850 of its stores across the country until October 31.
Britain's biggest supermarket Tesco told ITV News: “We’ve been updating our systems ready for the new pound coins, but to help customers who still have the old coins, we’ll continue to accept round pounds at our tills and self-service machines for an additional week.”
A trade association representing small shops has advised its members to continue accepting the round coins to provide a "useful community service" to customers.
The Federation of Small Businesses said: "It would help if small firms knew they were allowed a short transition period to collect the old coins if they wish to and are willing to bank them, but not give out to customers."
Major banks have said that they will continue to accept deposits of round pounds from their customers after October 15.
- Why was the new pound coin introduced?
There have been concerns about the old round pound's vulnerability to sophisticated counterfeiters.
The new coin has been described as the most secure coin in the world and boasts high-tech features, including a hologram.
About one in every 30 £1 coins given in change in recent years has been fake.
- What security features does it have?
The features include its 12-sided shape, its bi-metallic structure with a gold-coloured outer ring and a silver-coloured inner ring.
It also includes an image that changes from a "£" symbol to the number "1" when seen from different angles.
Additionally the coin has micro-lettering and milled edges.